Ongoing Clinical Trials for Prader-Willi Syndrome
Currently, there are 3 clinical trials investigating new treatments for Prader-Willi Syndrome. These studies are exploring medications aimed at managing excessive daytime sleepiness, addressing constant hunger, and supporting early development in children with this genetic condition. Trials are being conducted across multiple countries in Europe.
Clinical trial locations
- Belgium
- Czechia
- Denmark
- France
- Germany
- Italy
- Poland
- Romania
- Spain
- Sweden
Study on the Effects of Pitolisant Hydrochloride for Patients with Prader-Willi Syndrome
This trial is investigating pitolisant hydrochloride, also known as HBS-101 and marketed as WAKIX, for treating excessive daytime sleepiness in people with Prader-Willi Syndrome. The medication works by increasing certain brain chemicals that promote wakefulness and alertness.
Main inclusion criteria:
- Patients must be at least 6 years old
- Must have a confirmed diagnosis through genetic testing or medical records
- Must meet criteria for excessive daytime sleepiness based on specific questionnaires
- Must get an appropriate amount of sleep each night for their age
- Must have a consistent parent or caregiver willing to complete study assessments
- Female patients who can become pregnant must use reliable birth control and have negative pregnancy tests
- Patients with a history of seizures must have stable seizure patterns for at least 6 months
- Any long-term medications must be at stable doses for at least 30 days before and during the study
Main exclusion criteria:
- Patients without confirmed Prader-Willi Syndrome
- Patients outside the specified age ranges for the study
Study focus: The trial has two main phases. First, participants are randomly assigned to receive either pitolisant hydrochloride or a placebo for 77 days in a double-blind phase, meaning neither participants nor researchers know who receives the actual medication. This is followed by an open-label extension where all participants receive the active medication. Throughout the study, researchers will monitor changes in excessive daytime sleepiness severity, irritable and disruptive behaviors, and track any side effects to assess the medication’s safety.
The medication is taken orally as a tablet, with dosage adjusted based on individual response and side effects.
Study on the Safety and Effects of PBF-999 for Patients with Prader-Willi Syndrome
This trial is evaluating PBF-999, an investigational medication taken as a capsule, to determine its safety and tolerability in people with Prader-Willi Syndrome over a 28-day period.
Main inclusion criteria:
- Males and females between 12 and 65 years old
- Must have confirmed diagnosis through a DNA methylation test
- For adults, Body Mass Index up to 65 kg/m²
- Adults must have stable weight with no more than 10% change in the 3 months before the first visit
- Must have a reliable caregiver who has been providing care for at least 6 months
- Both participant and caregiver must provide written consent
- Women who can become pregnant must have negative pregnancy tests and use effective birth control
- Sexually active male participants and their partners must also use effective birth control
Main exclusion criteria:
- Patients without Prader-Willi Syndrome
- Patients outside the 12-65 age range
- Patients with health issues deemed unsafe by the study team
Study focus: Participants will take PBF-999 capsules orally once daily for 28 days. The study monitors how the body processes the medication and tracks any side effects. Regular check-ins are scheduled throughout the treatment period, and participants complete questionnaires about their health and well-being. At the end of the 28 days, a final evaluation includes physical examination and blood tests to assess the medication’s effects. The trial aims to target specific pathways in the body to help manage symptoms, although the exact mechanism is still under investigation.
Long-Term Study on Oxytocin for Children with Prader-Willi Syndrome Up to Age 4
This trial focuses on young children with Prader-Willi Syndrome and investigates the long-term safety of Otwillo, a nasal spray solution containing oxytocin. Oxytocin is a hormone that plays a role in social bonding and behavior.
Main inclusion criteria:
- Boys and girls with genetically confirmed Prader-Willi Syndrome
- Parents or legal representatives must sign consent forms
- For children who participated in the previous OTBB3 study: must be 16 months old (plus or minus 4 months), meaning between 12 and 20 months old
- For children who never received oxytocin treatment: must be 30 months old (plus or minus 6 months), meaning between 24 and 36 months old, and living in France
Main exclusion criteria:
- Children not within the specified age ranges
- Children with medical conditions other than Prader-Willi Syndrome that might make participation unsafe
- Children unable to follow study procedures or attend required visits
Study focus: This is a long-term follow-up study comparing children who received Otwillo treatment in a previous study with those who have never received oxytocin treatment. The study continues until children reach 4 years of age, with an estimated end date of June 2025. Researchers monitor the occurrence of adverse events, serious adverse events, and the development of health conditions commonly associated with Prader-Willi Syndrome. The study also tracks any medications, surgeries, or rehabilitation therapies children undergo, including details about type, timing, and frequency. The nasal spray is administered intranasally, with dosage and frequency determined by the study protocol and each child’s specific needs.
Summary
The three ongoing clinical trials for Prader-Willi Syndrome reflect diverse approaches to managing different aspects of this complex genetic condition. The largest trial, studying pitolisant hydrochloride, is being conducted across 10 European countries including Romania, Denmark, Spain, France, Sweden, Italy, Germany, Czechia, Poland, and Belgium, demonstrating significant international collaboration in addressing excessive daytime sleepiness.
Two trials focus on different age groups and symptoms: pitolisant targets patients aged 6 and older with excessive daytime sleepiness, PBF-999 focuses on adolescents and adults aged 12-65 to address the constant hunger characteristic of the condition, and the oxytocin study specifically targets very young children up to age 4 to support early development and prevent complications.
Spain appears twice as a trial location, hosting both the pitolisant and PBF-999 studies, while France is involved in both the pitolisant trial and the oxytocin study for young children. The concentration of trials in Western and Central Europe suggests strong research infrastructure and patient populations in these regions for rare genetic disorders.
Each trial uses different administration methods suited to its target population: oral tablets for older children and adults, capsules for adolescents and adults, and nasal spray for very young children. This variety reflects researchers’ efforts to develop age-appropriate treatments that address the diverse challenges faced by people with Prader-Willi Syndrome throughout their lives.
